Apparatus for withdrawing and storing filling yarn in stationary filling supply weaving machines

ABSTRACT

A system whereby a low and uniform withdrawal velocity is obtained at the filling yarn supply unit and a low and uniform withdrawal resistance exists in the filling yarn storage. A cylinder is provided with partitions extending helically around drum means. The cylinder has a perimeter matching the length of filling yarn to be stored around the drum means. The filling supply is storable and releasable under influence of a fluid relative to chambers formed by the partitions.

United States Patent [1 1 Scheffel Mar. 11, 1975 1 APPARATUS FORWITHDRAWING AND STORING FILLING YARN IN STATIONARY FILLING SUPPLYWEAVING MACHINES [76] Inventor: Walter Scheffel, lndustriestr. 53,

8832 Weissenburg, Germany [22] Filed: May 23, I973 [21] Appl. No.:363,138

[30] Foreign Application Priority Data May 23, 1972 Germany 2224933 Oct.9, 1972 Germany 2249393 [52] US. Cl 139/122 R [51] Int. Cl D03d 47/36[58] Field of Search 139/122 H, 127 P; 226/97, 226/117, 118; 242/182-185[56] References Cited UNITED STATES PATENTS 3,303,857 2/1967 Scheffel139/122 Reader 226/118 Brouwer 139/122 Primary E.\'aminerHenry S. JaudonAttorney, Agent, or FirmWa1ter Becker [57] ABSTRACT A system whereby alow and uniform withdrawal velocity is obtained at the filling yarnsupply unit and a low and uniform withdrawal resistance exists in thefilling yarn storage. A cylinder is provided with partitions extendinghelic ally around drum means. The cylinder has a perimeter matching thelength of filling yarn to be stored around the drum means. The fillingsupply is storable and releasable under influence of a fluid relative tochambers formed by the partitions.

10 Claims, 7 Drawing Figures APPARATUS FOR WITl-IDRAWING AND STORINGFILLING YARN IN STATIONARY FILLING SUPPLY WEAVING MACHINES Thisinvention relatesto apparatus for withdrawing and storing the fillingyarn in machines for making weblike fabrics, such as weaving machineshaving the filling yarn supply unit outside the shed of warp threads,etc., said apparatus being arranged in the path of the fillingyarn-between the filling yarn supply unit and the weaving machine andincorporating at least one mechanicaldrive drum to withdraw the fillingyarn from the filling yarn supply unit around which drum the fillingyarn is storable and releasable under the effect of a fluid.

It is known in the manufacture of web-like fabrics, such as wovenmaterials, etc., to use machines adapted to work the individual threadsinto web-like fabrics, such as woven cloths, etc. lnweaving machines,for instance, it is knownto insert filling yarn in a transversedirection between thelongitudinal warp threads and to batten or push thefilling yarn in place against the warp threads by means ofa reed. Forthe purpose of inserting the filling yarn or picking, mechanicalconveying means are predominantly used having grippers or carriers forthe filling yarn and, depending on the method of propulsion, convey thefilling yarn across the full width of the woven material or web-likefabric to be made or over a certain distance after which the fillingyarn is picked up by another gripper or carrier to complete the pick.Although the conveying means pick up and insert the filling yarn in theshed of warp threads carefully, the instantaneous pulling moment isliable to cause considerable tension stresses in the filling yarn which,if the filling yarn supply unit fails to yield sufficiently, inparticular if the filling yarn is stuck or otherwise fails to unwind,results in the filling yarn breaking. These drawbacks of the directwithdrawal of the filling yarn from the filling yarn supply unit detractfrom the performance of the machine. Similar drawbacks tend to exist inwarp knitting where similarly a filling yarn has to be inserted in orderto be worked into the knitted fabric by the individual needles.

In order to overcome these drawbacks, systems have become known that arearranged between the weaving machine and the filling yarn supply unitand designed to withdraw the filling yarn from the filling yarn supplyunit before it is conveyed through the warp threads in a mannner thatthe conveying means need not pull against the resistance of the fillingyarn supply unit. Whilst this enables the tension in the filling yarnduring its conveyance through the warp threads to be reduced, it willnot prevent the filling yarn from whorling or ballooning periodicallyeach time a pick is withdrawn from the supply and inserted in the shed(cf. German Patent Specification No. 817,875).

With a view to avoiding ballooning it is furthermore known to provide asystem between the weaving machine and the filling yarn supply unitserving both to withdraw the filling yarn from the filling yarn supplyunit and to store it for conveyance through the shed. One such deviceprovides for thefilling yarn to be periodically withdrawn axiallytowards the front end of the storage winding, although againit will notsuppress ballooning. This ballooning of the filling yarn results instress peaks, although under more readily controllable conditions thanwhere the filling yarn is directly withdrawn from the supply and, infact, the device referred to fails to achieve its objective, namely toeliminate ballooning. Moreover, systems of this type are very complex,expensive and vulnerable, because they require a system to regulate thelength of the filling yarn on the winding element of the storage device(cf. German Patent Specification No. 1,258,809).

Furthermore, there are known systems designed as conveying storagedevices featuring tangential filling yarn withdrawal whereby ballooningis avoided, but these systems afford only inadequate withdrawal of thefilling yarn from the supply even where considerable energy isappliedQWhere winding on the supply unit is faulty or otherobstructions, such as knots, etc., exist in the filling yarn supply,this would cause withdrawal re- I sistances to be set up that theconveying force of the storage device cannot overcome so that thestorage will not be completely filled and, consequently, will fail toexercise its tension-reducing effect (cf US. Pat. No. 3,477,476),

Accordingly, the present invention has for its object to provide asystem whereby a low and uniform withdrawal velocity is obtained at thefilling yarn supply unit and a low and uniform withdrawal resistance inthe filling yarn storage. In addition, this invention is intended tosolve the problem of withdrawing and storing the filling yarn withoutballooning taking place.

This object according to the invention is achieved in a system of thetype referred to initially by having a cylinder with a perimetermatching the length of filling yarn to be stored disposed around a drumor drums, the cylinder being provided with partitions extendinghelically around the drum or drums and the shell of the cylinder beingformed with surfaces for the stored filling yarn and ports allowingfluid to escape from the chambers formed in the cylinder by thepartitions.

These features afford the advantage that the amount of filling yarnstored is restored after each pick to the same value that is necessaryfor low-tension insertion of the filling yarn into the fabric to beformed, the action being entirely self-regulating. This is achieved byimparting an initial tension to the helical coil of thread near theoutlet of the storage device under the action of a fluid flowingradially outwards from the inside againstthe thread coils. In the coilsof the filling yarn lying nearer the inlet of the storage device andthose contacting the rotating drum, this initial tension produces atension that is greater than the initial tension. This physical effectis generally described as the rope friction effect and defined by thefollowing formula:

In this formula S is the thread tension existing at the outlet side inthe storage device at the point where the filling yarn just lifts offthe rotating drum. S is the thread tension existing at the inlet of thestorage device at the point where the filling yarn winds tangentiallyonto the drum. The value e is the basis of the natural logarithms and uis the friction coefficient for the friction between the filling yarnand the drum. The are measure for the thread length lying on the drum isgiven by a.

If, for instance, due to the initial tension 5,, the tension S isgreater than the withdrawal resistance at the filling yarn supply unit,then the filling yarn is withdrawn from the filling yarn supply andconveyed into the storage device or system. The increase in the amountof thread contained in the storage device causes an increased length ofthread to be lifted off under the effect of the fluid and taken towardsthe envelope of the chamber. Simultaneously, the are a shortens, causingthe tension S to be reduced until the filling yarn at the inlet of thestorage device soon becomes stationary again. The storage action residesin the fact that the length of filling yarn entering causes the diameterof the'thread coils already contained in the storage device to increase.If a slight pull is exerted on the outlet-side strand of the thread,filling yarn will come out of the storage device, whereby the diameterof the outlet-side thread coils in the storage device will decrease,resulting in a longer thread length contacting the drum than before. Theincrease in the are a of contact between the thread and the rotatingdrum or drums produces a higher thread tension 5,. This, in turn,initiates the cycle of conveying and storing already described so thatthe initial state is soon restored. In other words, the filling yarn inthe system according to the invention is not withdrawn against themoment of the filling yarn supply unit but withdrawn from the storagepractically without the resistance of an opposing force. These featuresalso go a long way towards preventing breakages of the filling yarn dueto the tensions liable to arise with conventional withdrawal systems,thus minimizing disturbances of production. Control of breakages of thefilling yarn also prevents knots occurring in the fabric which detractfrom its quality.

According to a further feature of the invention, the chambers providedaround the drum or drums may be disposed helically adjacent to eachother.

This helical arrangement of the individual chambers around the drum ordrums enables an orderly storage of the filling yarn to be obtained sothat it will not tangle inside the cylinder. According to yet anotherfeature of the invention, the edges of the partitions facing the drum ordrums are disposed with a clearance between said edges and the drum ordrums. This clearance is a special asset where the system is providedwith drums arranged to be driven for the purpose of assisting themovement of the filling yarn. In order that the filling yarn can beconveniently withdrawn from the individual chambers, each partition isformed with at least one radial slot for the threading of the fillingyarn.

For the purpose of admitting the fluid which, as a rule, will be agaseous medium, into the cylinder, provision is made for at least onesupply pipe for the fluid in the area of the axes of rotation of thedrum or drums, the supply pipe being formed with radial outlet ports forthe fluid inside the cylinder.

It is within the scope of this invention to arrange the fluid supplypipe either inside the drum or, where several drums are used inside thecylinder, outside the drums.

According to an advantageous improvement of the invention, where severaldrums are provided, a plurality of fluid supply pipes may be disposedbetween the drums with their radial outlet ports directed towards theinner surface of the cylinder.

For further advantageous improvements of the invention, reference ismade in particular to the remaining subclaims. Two typical embodimentsof the invention are shown schematically in the drawing in which:

FIG. 1 shows a cylinder with two drums arranged inside it for a fillingyarn to be stored having chambers arranged helically around the drumsinside the cylinder,

FIG. 2 is a cross section through FIG. I including a section through onedrum.

FIG. 3 is a plan view of the system illustrated in FIG.

FIG. 4 shows a system having only one drum arranged inside the cylinderand chambers disposed in parallel around this drum for the filling yarn,

FIG. 5 is a cross section through the system illustrated in FIG. 4,

FIG. 6 is a plan view of the system illustrated in FIG. 4, and

' FIG. 7 shows a weaving machine with a storage sys tem and filling yarnsupply unit arranged at its side.

The system according to the invention is explained and described asapplied to the example of a weaving machine it being arranged between ashed of threads 23, a weaving machine 24 and a filling yarn supply unit25. The weaving machine is provided with insertion means 28 forinserting a filling yarn 26 through the shed of a plurality of warpthreads 27. The insertion means 28, which, for example, may be of themechanical type are shown in the form of tapes arranged on drivablepulleys 29. Each tape end of the insertion means in the embodiment shownhere is provided with a gripper or carrier 30 and 31 for the end of thefilling yarn 26, one of the carriers, say 30, being so designed as tonot only pick up the end of the filling yarn, but also to transfer it tothe other carrier 31. Cutting means 34, for instance, scissors orsimilar systems, are provided on the weaving machine 24 to cut thefilling yarn 26 to length after insertion through the warp threads 27 ora picking at the entry side of the filling yarn into the shed 23.Furthermore, a thread clamp 32 is provided there serving to keep thecutt off filling yarn ready for the insertion of the next pick.

The embodiment of the invention illustrated in FIGS. 1, 2 and 3 ischaracterized by two rotating drums l and 2 and, arranged helicallyaround these, stationary partitions 3 of a cylinder 33 containing allthese elements. The strand 4 of the filling yarn 26 coming from thefilling yarn supply unit 25 enters the system at the inlet edge 5. Therethe filling yarn 26, the strand of which inside the cylinder 33 isdesignated by 6, runs helically around the drums l and 2. The strand 7of the filling 26 running to the weaving machine 24 leaves the storagesystem at the outlet edge 8. It is implied that the strand 4 as well asthe strand 7 can also enter and leave the individual chambers 13 throughopenings in the envelope surface 14 of the cylinder 33. The two drums 1and 2 rotate in the same sense and are operated by a drive 9. Thesurface velocity of the individual drums is equal and at least as highas the velocity of the yarn occurring in the strand 7. Through astationary bearing 10 of the drums l, 2, a fluid, in this case air atabove atmospheric pressure, is admitted through an inlet 11 into thedrums'to'flow through passages 12 formed as radial holes in the drumsinto the chambers 13. From the chambers 13 which are formed by thepartitions 3 and their outer envelope 14, the air is discharged toatmosphere through the passages 15. The shell of the cylinder 33, Le.its envelope 14, is detachable in order that the filling yarn 26 can beinserted into the storage system before starting operation. Thepartitions 3 of the chambers 13 surround the drums 1, 2 with arelatively small clearance, a free gap 16 being left free between thepartitions and the drums. In this embodiment of the invention, thefilling yarn 26 is pulled into the cylinder by rotating drums l, 2 onthe one hand and the admission of the fluid, the filling yarn graduallyrunning onto the inner perimeter of the cylinder. In this process, eachcoil of the filling yarn 26 lies in a separate chamber 13 so that thereis no possibility of the filling yarn tangling inside the cylinder 33.

In the embodiment of the invention illustrated in FIGS. 4, 5 and 6, thestorage system has been simplified somewhat inasmuch as there is only asingle drum 1 instead of two drums l, 2. This embodiment also has thepartitions 17, 18 and 19 of the chambers 13a and 13b straight around thedrum 1 instead of helically. The strand 4 enters through a radial slot20 provided in the first partition 17 into the chamber 13a. In thischamber 13a, the filling yarn 6 wraps around the drum 1 once and thenpasses through another slot 21 into the next chamber 13b. Theoutlet-side strand 7 leaves the chamber 13b through another slot 22 torun on to the weaving machine 24. Similar to the preceding embodiment ofthe invention it is also implied that the inlet and outlet of thestrands 4 and 7 may be through openings in the shell of the cylinder 33.A pressurized fluid, such as air in this case, is admitted through aninlet 11 in the bearing system of the drum 1 to the passages 12 in thedrum to flow through these radial passages into the chambers 13a and 13bwhich it again leaves through the ports 15 in the shell or envelope 14of the cylinder 33. The coils formed by the filling yarn 6 around thedrum 1 increase in diameter under the influence of the radial flow ofthe fluid to lie against the inner surface ofthe shell 14. The surfacevelocity of the drum is constant and at least as high as the maximumvelocity of the strand 7 occurring. In the embodiments illustrated thesupply of a fluid is represented as being through the individual drums 1and 2 formed with radial ports 12. In cases where the supply cannot betaken through the drums, it is also possible, especially where severaldrums are used inside a cylinder 33, to arrange the supply pipes outsidethe drums, as exemplified by the dashdot line in FIG. 1. In thisconfiguration, the fluid supply pipes are disposed in parallel to therotating axes of the drums, but they are outside the drums and havetheir radial ports directed towards the inner surface of the cylinder.The use of such fluid supply pipes can be an advantage especially whereradial ports in the drums 1, 2 are to be avoided, or where sealing is aspecial problem in taking the fluid supply through the drums.

As described in the foregoing, the helical coils of yarn are separatedby partitions. This means that a new partition follows after every 360arc of the yarn winding. Two typical alternatives are described andrepresented in the embodiments referred to above, namely a parallelarrangement and a helical arrangement of the individual partitions. Theparallel partitions are disposed perpendicularly to the axis of therotating drum and are formed each with a slot shaped radial penetra:tion serving to transfer the filling yarn into the next chamber. If thepartition or separating surface is formed as a helical surface, thesepenetrations are not needed because the partition will then follow thehelical yarn coil at a uniform spacing. Between each partition and thenext, there is an outer envelope, i.e., the shell of the cylinder whichconnects the outer perimeter of the chamber. This envelope is permeableand permits the fluid to-escape outwards, while controlling the size ofthe yarn coils as the filling yarn is laid onto the inside of thisenvelope. Together with the partitions, this envelope forms the chambersreferred to earlier of which each accommodates one coil of yarn. Thenumber of chambers can be chosen at will. It is thus possible to have agroup of adjacent chambers handle one yarn and the subsequent chambersanother yarn. This results in a storage system according to theinvention for multicolour weaving machines. Compared to the storagesystem according to the invention for storing and conveying one yarn,the multiple version is bigger, but not more complex. Known systems forthe same purpose involve a separate additional system for eachadditional yarn whereby the costs and the complexity increaseproportionately. lf filling yarn is withdrawn periodically or cyclicallyby the weaving machine from the storage system filled according to themethod proposed by the invention and, if the stored length of yarn isgreater than the length required for a pick, the tension at the outletof the storage system will be low and uniform. The velocity ofthefilling yarn leaving the storage system is determined in the systemaccording to the invention by the weaving machine itself, whereas thevelocity of the yarn entering is regulated by a straighforward physicalprinciple in a manner that the storage system is filled up again once aperdetermined length of yarn has been withdrawn. The use of thisprinciple enables a straightforward storage system to be obtained at lowcost and with a high efficiency.

What we claim is:

1. Apparatus for weaving machines having a warp shed including means todefine a path'and a system for withdrawing and storing of filling yarnin machines for making web-like fabrics with a filling yarn supply beingoutside the warp shed, said withdrawing and storing system being locatedin the path of the filling yarn between the filling yarn supply and theweaving machine and incorporating at least one mechanically-driven drummeans for withdrawing the filling yarn from the filling yarn supply, thefilling yarn being controlled about said drum to be alternately storedand released under the influence of fluid, means including portionshaving edges arranged to form chambers collectively around the drummeans and a cylinder having a shell defining a perimeter matching thelength of the filling yarn to be stored around said drum means, siadshell having surfaces to deposit the stored filling yarn and havingopenings for the discharge of fluid from the chambers formed by thepartitions of the cylinder.

2. Apparatus as in claim 1, characterized in that said further meansincluding partitions to form the chambers provided around the drummeansare arranged helically adjacent to each other.

3. Apparatus as in claim 1 characterized in that said edges ofthepartitions facing the drum means surround the drum means with aclearance therebetween.

4. Apparatus as in claim 1 characterized in that each partition has atleast one radial cut-out for the threading of the filling yarn.

5. Apparatus as in claim 1 characterized in that said cylinder hasopenings in its shell for the entry and exit of the filling yarn.

6. Apparatus as in claim 1 further characterized in that the cylinderhas radial cut-outs in its outermost partitions of which one is formedas an inlet edge and the other as an outlet edge for the entry and exitof the filling yarn.

9. Apparatus as in claim 8, further characterized in that said fluidsupply pipe passes through said drum means when only one drum means isused.

10. Apparatus as in claim 8, further characterized in that said fluidsupply pipe is arranged outside said drum means and is located in thecylinder, said fluid supply pipe being provided with radial dischargeports.

1. Apparatus for weaving machines having a warp shed including means todefine a path and a system for withdrawing and storing of filling yarnin machines for making web-like fabrics with a filling yarn supply beingoutside the warp shed, said withdrawing and storing system being locatedin the path of the filling yarn between the filling yarn supply and theweaving machine and incorporating at least one mechanically-driven drummeans for withdrawing the filling yarn from the filling yarn supply, thefilling yarn being controlled about said drum to be alternately storedand released under the influence of fluid, means including portionshaving edges arranged to form chambers collectively around the drummeans and a cylinder having a shell defining a perimeter matching thelength of the filling yarn to be stored around said drum means, siadshell having surfaces to deposit the stored filling yarn and havingopenings for the discharge of fluid from the chambers formed by thepartitions of the cylinder.
 1. Apparatus for weaving machines having awarp shed including means to define a path and a system for withdrawingand storing of filling yarn in machines for making web-like fabrics witha filling yarn supply being outside the warp shed, said withdrawing andstoring system being located in the path of the filling yarn between thefilling yarn supply and the weaving machine and incorporating at leastone mechanically-driven drum means for withdrawing the filling yarn fromthe filling yarn supply, the filling yarn being controlled about saiddrum to be alternately stored and released under the influence of fluid,means including portions having edges arranged to form chamberscollectively around the drum means and a cylinder having a shelldefining a perimeter matching the length of the filling yarn to bestored around said drum means, siad shell having surfaces to deposit thestored filling yarn and having openings for the discharge of fluid fromthe chambers formed by the partitions of the cylinder.
 2. Apparatus asin claim 1, characterized in that said further means includingpartitions to form the chambers provided around the drum means arearranged helically adjacent to each other.
 3. Apparatus as in claim 1characterized in that said edges of the partitions facing the drum meanssurround the drum means with a clearance therebetween.
 4. Apparatus asin claim 1 characterized in that each partition has at least one radialcut-out for the threading of the filling yarn.
 5. Apparatus as in claim1 characterized in that said cylinder has openings in its shell for theentry and exit of the filling yarn.
 6. Apparatus as in claim 1 furthercharacterized in that the cylinder has radial cut-outs in its outermostpartitions of which one is formed as an inlet edge and the other as anoutlet edge for the entry and exit of the filling yarn.
 7. Apparatus asin claim 1 further characterized in that each filling yarn includes athread that has assigned to it at least one chamber with inlet andoutlet edges.
 8. Apparatus as in claim 1 further characterized in thatat least one fluid supply pipe is provided in the zone of rotation ofthe drum means and that this fluid supply pipe is provided inside saidcylinder having radial discharge ports for the fluid.
 9. Apparatus as inclaim 8, further characterized in that said fluid supply pipe passesthrough said drum means when only one drum means is used.